1. Field of the Invention
The present invention relates to a fuel cell.
2. Description of the Related Art
Basically, a fuel cell comprises a plurality of cells stacked one above another to be electrically connected in series. The greater the area of the cell, the greater the capacity of the fuel cell. On the other hand, there is limit in enlargement of the cell area from the view point of manufacture or cost. Hence, a fuel cell relating to the present invention is of a type where a plurality of cells are juxtaposed the direction of the plane of the cell in such manner that opened end faces (hereinafter, `opened sides`) of the adjacent cells, to which inner cell flow passages of the cells are opened, are opposed to each other. The juxtaposed cells together constitute one `cell layer`; then a plurality of these cell layers are stacked one above another in serial connection with each other, so as to increase the capacity of the fuel cell.
In such type of fuel cell described supra, in order to connect the adjacent cells in each cell layer and also to stack the plural cells layers to constitute a multi-layered fuel cell assembly, the convention has suggested a construction as shown in FIG. 25. In this construction, a cell assembly NC includes: a first plate member 70 having an accommodating portion 71 having a substantially same thickness as a cell C and functioning to accommodate a cell layer nC and a pair of partition wall portions 72 with which closed sides of the respective cells, to which the inner cell flow passages x of the cells are closed, are placed in sealed contact; and a second plate member 80 having plural of inter-cell flow passage forming openings 81 exposed to the cells C accommodated in the first plate member 70 and plural of mounting portions 82 for mounting thereon opened side edges of the cells C of the cell layer nC accommodated in the first plate member 70 to which side edges the inner cell flow passages x of the cells are opened, with plural of first plate members 70 accommodating the cell layers nC and plural of second plate members 80 being alternately stacked one one another. In this stacked condition, the mounting portions 82 of the second plate members 80 support the adjacent cells C of a same cell layer nC and also support these cells C with a predetermined distance from those further cells C of vertically adjacent cell layers nC. Further, adjacent cells C of a same cell layer nC are partitioned from each other by the pair of partition wall portions 72 of the first plate member 70 and the mounting portions 82 of the second plate members 80 adjacently disposed on and under the first plate member 70, so as to form connecting flow passages z. In short, in the conventional construction, cell connector members T comprise the first plate member 70 and the second plate member 80.
However, in the case of the conventional construction, the greater the number of cells constituting each cell layer, the larger the first and second plate members should be formed. However, since there is limit in enlargement of these plate members in view of dimensional precision and possibility of warping thereof, it is impossible to un-limitedly increase the number of cells for constituting the cell layer. Accordingly, there has remained room for improvement in the respect of enlargement of the capacity of the fuel cell.
The present invention has been made in view of the above-described state of the art and its object is to further increase the capacity of a fuel cell.